1. Field of the Invention
This invention relates to a concrete joint in concrete slab structures in which the joint includes an insert that is retained in centered position in a slot or recess formed in the upper surface of a concrete slab generally in alignment with a crack or fracture line extending downwardly from the slot or recess formed in the concrete slab. The bottom of the slot or recess is provided with a seal of cementitious material which extends completely across the bottom of the slot or recess and fills the crack or fracture line with the lower edge of the insert being inserted partially into the cementitious seal which is in the form of a quick setting sand and cement mixture which has high compression strength and low tensile strength and which will adhere to concrete surfaces but will not adhere to the insert. The space above the bottom seal on each side of the insert is then filled with a filler of an epoxy or similar material which encapsulates the spring clips and fills the slot or recess on both sides of the insert.
2. Description of the Prior Art
My prior Pat. No. 4,875,802 issued Oct. 24, 1989 for Installational Concrete Joint Insert and Method of Preventing Edge Spalling discloses a solution to edge spalling of expansion joints in concrete slabs and discusses the existing problems and provides a solution to those problems. The disclosure in the above-mentioned patent and the prior art made of record therein are incorporated herein by reference thereto. The disclosure in the aforementioned patent and the prior art of record therein does not include spring clips for retaining the insert in position as disclosed in this application and does not disclose a quick set cement and sand seal for the bottom of the slot or groove which precludes the epoxy type filler from migrating into the crack or fracture line which would bond the adjacent concrete surfaces with such rigidity that the edge of the concrete joint could "refracture" by a fracture line extending from the surface of the concrete slab structure to a crack or fracture line below the slot or recess at a position laterally spaced from the side edges of the slot or recess in the concrete slab.